Heavy Towing: Electric fans or clutch fan?

[Aruba1]

I just been doing some research and I came to this site to ask a question if I should install a clutch fan on my 5.3L 1972 C30 as some people claim that electric fans will NEVER be able to move as much air as a clutch fan.

I am not too concerned with horsepower. IN my case I have a lot of issues with high temperature in traffic or when towing up a hill. I would like to go with clutch fan to fix this issue. The other option is get someone to tune my PCM ($250) to get the fans to come on earlier, stay on longer and add some more changes to take advantage of my exhaust system (headers, flowmasters, etc), cold air intake, 5 speed manual (versus the current automatic tune), 4.10 rear differential, etc.

Being my cooling system is most important to me, which one should I go with? Is it true that clutch fan move a lot more air than electrics?Some people claim 9,500 CFM at 1,800 rpm, does this sound right? Thanks